A gas turbine engine commonly includes a fan section, a compressor section, a combustor, and a turbine section axially aligned sequentially through the engine. Typically, a fuel system delivers to the engine combustor a uniform flow of clean fuel at the proper pressure and in the necessary quantity to operate the engine. Despite widely varying operational conditions, the fuel supply must be adequate and continuous to meet the demands of the engine.
A typical fuel system for gas turbine engines may comprise a fuel pumping arrangement, a common manifold that extends from the pumping arrangement across the top or side of the engine, and individual fuel lines that extend from the manifold to individual fuel injectors in the combustor. Further, a number of fuel delivery tubes and components that must be connected together by fuel line connections are sometimes disposed near the hot portions of the gas turbine engine.
During operation, the main fuel delivery tube is pressurized and supplies fuel to the other fuel delivery tubes en route to the combustor. Since the fuel is delivered under considerable pressure, all fuel line connectors must be able to withstand continued exposure to such high fuel pressure. Any fuel undesirably exiting through such connectors will degrade engine performance. The release of fuel from such fuel line connectors near hot portions of the engine is particularly important to avoid.
In addition, the lubricant system for gas engines may also include lubricant line connectors which must consistently contain and prevent exit of same for similar reasons. Such fluid connectors in an engine may be provided in any number of different forms such as, but not limited to, ferrules, B-Nuts, and other couplings. Such fluid connectors may be welded or otherwise secured onto fluid transferring tubes, such as, for example, the aforementioned fuel lines or lubricant lines, etc.
The prior art has typically employed metallic spray shields at such connectors to prevent fuel, lubricant, or other fluids unexpectedly exiting from such fluid connectors from contacting hot portions of the engine. These metallic spray shields are typically custom-made and individually installed. Not only are these metallic spray shields expensive, they also require proper installation, special tooling, and considerable time and special skills to make/install. Moreover, the nacelle in current engine designs is substantially reduced in size and thus increases the level of difficulty in properly positioning and attaching such rigid metallic spray shields onto the fluid line systems. This situation is made even more challenging given the tight tolerances under which such systems are manufactured, and the high number of parts used in dense locations around the fluid connectors.
To better answer the challenges raised by the gas turbine industry to produce reliable and high-performance gas turbines engines, it can therefore be seen that improvements in such fluid line connectors are needed.